one of the first 'modern' hydroponics publications

zem

Well-Known Member
i only use the hoagland solution for reference because is outdated,. it does not work well for weed, as weed in particular needs a much higher P content than whats in hoagland recipe. its npk is 210-31-236 thats 7to1 ratio, weed requires something around 6-3-8 that is 2 or 3 to 1 ratio. Also, it does not contain a lot of ingredients that are used in new ferts, like ammonium nitrate, magnesium nitrate, calcium oxide, potassium oxide, silica etc.. etc... i was able to identify the most incredible chemical in one of GH ferts, that is called " Nitric acid, ammonium calcium salt " http://www.chemspider.com/Chemical-Structure.2338439.html
I worked with the ingredients of hoagland recipe for years, i thought the others were not needed until i began getting a wider variety and i noticed a huge difference. There is a reason why hydro ferts contain a certain level of ammonia, that is because it is beneficial at correct doses. And yes you can grow without silica but plants still grow better when it is available.
 

Yesdog

Well-Known Member
i only use the hoagland solution for reference because is outdated,. it does not work well for weed, as weed in particular needs a much higher P content than whats in hoagland recipe. its npk is 210-31-236 thats 7to1 ratio, weed requires something around 6-3-8 that is 2 or 3 to 1 ratio. Also, it does not contain a lot of ingredients that are used in new ferts, like ammonium nitrate, magnesium nitrate, calcium oxide, potassium oxide, silica etc.. etc... i was able to identify the most incredible chemical in one of GH ferts, that is called " Nitric acid, ammonium calcium salt " http://www.chemspider.com/Chemical-Structure.2338439.html
I worked with the ingredients of hoagland recipe for years, i thought the others were not needed until i began getting a wider variety and i noticed a huge difference. There is a reason why hydro ferts contain a certain level of ammonia, that is because it is beneficial at correct doses. And yes you can grow without silica but plants still grow better when it is available.
Yeah, definitely see more modern variants. As far as P, I've been doing a lot of research that seems to advise keeping P below 50ppm. Most plants are actually rather P hungry, and its arguably one of the largest limits on growth (P available, next to N availability). The main issue is that its not very soluble with cal/mag and causes these big and slow buffering reactions that can cause trouble with uptake and pH easily (behaves and scales much like carbonates). I guess the other issue is that plants don't normally encounter 'excess P' in soil, so there's lots of genetic variations on how they handle it. Normally the excess P in soil scales off and adsorbs onto solid materials, so only minimal available in the root zone.

Ammonium is definitely really cool, from what I was reading about that.... plants can normally manage nitrates really well and there's little chance of nitrate toxicity at most concentrations. However, ammonium behaves like most cations to the roots- they just kinda take em regardless of demand, issue is they're metabolized in the plant and become nitrates- big theory is thats the 'N toxicity' you would mostly see with commercial fertilizers, ammonium overdose.

But, when it's given to the plant in the right dose, its supposed to be a a big veg booster. The 'forced nitrates' encourage the plant to add more growth and/or boost metabolism. P is supposed to do something similar (excess P can encourage growth) I guess again because the plant cant get rid of it, so its only option is to just add more plant to balance things out. Trying to remember what and where I read it, but was around 30-50ppm recommended. I guess if you really look at it, nitrates and potassium are the most soluble and stable in solution.

Anyways, kinda rambly. Will eventually cobble this information together with links in a thread one day for some real discussion and whatnot
 
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